This invention relates to microscope slides and the like and to a method for manufacturing such slides. In many applications of a microscope slide, it is desired to have a grid pattern on the slide for measurement purposes. Such a grid needs to have closely spaced lines and very thin lines in order to be of value at the high magnifications utilized in a microscope.
Two general approaches have been used in preparing such slides in the past and both are relatively expensive. In one prior art approach, a pattern is produced in the glass of the slide, as by etching or sandblasting. One embodiment of this approach is shown in U.S. Pat. No. 3,481,659.
In another prior art procedure, a coating in the form of a ceramic glaze or a metal film is applied on the glass substrate and the grid is ruled through the coating as by using a diamond tipped tool. The ruling method is shown in U.S. Pat. Nos. 1,994,483; 2,328,585; and 2,660,091.
It is an object of the present invention to provide a new and improved microscope slide wherein the grid can have very fine lines with very close line spacings. A further object is to provide such a slide where the grid can be quite thin and positioned at the working surface of the substrate so that the image of the grid is sharply defined at the substrate surface, providing an indication of proper focus of the microscope. A further object is to provide such a slide which is relatively inexpensive to manufacture, while utilizing proven manufacturing techniques. An additional object is to provide a grid with indicia in zones for identifying individual zones. Another object is to provide a colored grid on a colorless substrate.